Mesenchymal stem cells are known to have pleiotropic actions. They exert trophic and anti-inflammatory effects on damaged tissues by producing a variety of factors and cytokines that act to protect tissues, but also modulate immunological reactions. The property of MSCs to undergo broad spectrum of differentiation beyond the boundaries (mesodermal to ectodermal and endodermal) between germ layer lineages and healing wide variety of injured tissues elucidate the curiosity among basic researchers.

The new discoveries, the extraordinary dynamism in human stem cell (SC) research, and the great expectations of the benefits in clinical treatment of many diseases are on the edge of unparalleled advances in understanding of basic mechanisms of cell differentiation and development and the translation from basic research to new clinical therapies.

They are emerging as a promising therapeutic approach of cell-based therapy for a wide range of autoimmune disorders and degenerative diseases. The beneficial effects of adult stem cells are considered to be associated with their homing efficiency to the tissue injury sites, differentiation potential, capability to produce a large amount of trophic factors, and their immunomodulatory effect. In preclinical and clinical studies, MSCs have been shown to be highly efficient in treating graft-versus-host disease, systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, myocardial infarction, liver cirrhosis, inflammatory bowel disease, and other disorders.

Unlike ES or iPS cells, MSCs have no ethical issues and have a low risk of forming teratomas. Nevertheless, pilot studies have demonstrated that MSCs are largely safe in vivo, and they are currently the most widely used stem cells in clinical settings.

The advancement of knowledge within developmental biology concerning the formation of tissues and the specialization of cells, as well as their interactions with surrounding tissues and organ development, has resulted in completely new principles of treatment. They are studied along with the research on germ cells and fertilization as well as research on infertility, in vitro fertilization and organogenesis. Potential downstream applications consider the use of human fetal MSCs as a target cell for non-invasive pre-natal diagnosis from maternal blood, and for fetal cellular and gene therapy.

MSCs have gained a great deal of attention in the expectation of their contribution to regenerative medicine because of several beneficial aspects. They can be collected from easily accessible tissues, such as bone marrow, lipoaspirate and the umbilical cord, and can be stably expanded to a large number of cells within a reasonable time period. Collection of MSCs avoids ethical concerns unlike embryonic stem cells and do not have a tumorigenic proliferative activity. Thus, they are considered one of the most suitable stem cell types for cell based-therapy. In fact, some clinical trials have been diligently conducted using MSCs.

An important application of stem cells, in addition to cell therapy, is in the discovery of novel drugs, giving many advantages over currently used methods at all stages of the process from target identification to high throughput screening through to toxicology studies. The capability to generate MSCs from iPSCs also opens the possibility of generating disease-specific MSCs that could be used to study disease progression and phenotype in vitro as well as to study the effect of drugs across multiple genetic backgrounds.